That can't be correct. Revelation 5:9-10 (WEB)
(9) They {the 24 elders} sang a new song, saying, “You are worthy to take the book, and to open its seals: for you were killed, and bought us for God with your blood, out of every tribe, language, people, and nation,
(10) and made us kings and priests to our God, and we will reign on the earth.”
1 Peter 2:9-10 WEB
(9) But you are a chosen race, a royal priesthood, a holy nation, a people for God’s own possession, that you may proclaim the excellence of him who called you out of darkness into his marvelous light:
(10) who in time past were no people, but now are God’s people, who had not obtained mercy, but now have obtained mercy.
The "Biblical fathers of Israel" were not people from "every tribe, language, people and nation" - Christians are. Only Christians are promised to become priests and kings (a "royal priesthood") and to share in Christ's reign over the earth:
Romans 8:16-17 WEB
(16) The Spirit himself testifies with our spirit that we are children of God;
(17) and if children, then heirs; heirs of God, and joint heirs with Christ; if indeed we suffer with him, that we may also be glorified with him.
2 Timothy 2:11-12 WEB
(11) This saying is trustworthy: “For if we died with him, we will also live with him.
(12) If we endure, we will also reign with him. If we deny him, he also will deny us.
Revelation 20:6 WEB
(6) Blessed and holy is he who has part in the first resurrection. Over these, the second death has no power, but they will be priests of God and of Christ, and will reign with him one thousand years.
Only Christians, members of the body and bride of Christ, have a part in the first resurrection. From Hebrews 11, Abraham, Sarah, Isaac, Jacob, Joseph, Moses, Rahab, Gideon, Barak, Samson, Jephthah, David, Samuel, and the prophets:
Hebrews 11:39-40 WEB
(39) These all, having had testimony given to them through their faith, didn’t receive the promise,
(40) God having provided some better thing concerning us, so that apart from us they should not be made perfect.
i.e. Christians have to be resurrected first before these Old Testament "fathers of Israel" could be made perfect (resurrected).
Concerning the 144,000 you said:
They can't be, because the 144,000 don't become the 144,000 sealed Israelites until after the resurrected Church in heaven witness Jesus take the scroll from God (just before Revelation 5:9 that I quoted above) and then open the first six seals, resulting in the Great Tribulation coming upon those on the earth (Revelation 6:17 - "for the great day of his wrath has come; and who is able to stand?”). Only then are the 144,000 mentioned, and they are described as being servants of God, whereas Christians are children of God (as quoted in Romans 8:16 above).
The remnant of Israel that Paul mentions in Romans are the Jews who became the first Christians, with the apostles and disciples not preaching to the Gentiles until about 3.5 years after Jesus' resurrection, when Peter was sent to Cornelius (Acts chapter 10).
They are sealed with God's seal (the Name of God and of the Lamb of God) so that the four destroying angels to whom it was given to harm the earth and the sea (Revelation 7:2) could avoid hurting those sealed.
They can't be among the "dead in Christ" because the first resurrection had already taken place and all the dead Christians had been resurrected and raptured, and are with Christ in heaven, whereas the 144,000 Israelites are living on the earth and go through the Great Tribulation.